Automotive seat based microclimate system

ABSTRACT

A method of controlling a microclimate system includes identifying a set of multiple microclimate thermal effectors configured to provide multiple occupant zones and determining a differential temperature between a local temperature at one of the microclimate thermal effectors and a preset temperature for the microclimate thermal effectors. The differential temperature is determined for each of the microclimate thermal effectors. A fuzzy set is generated for each of the microclimate thermal effectors based upon the respective differential temperature. A respective temperature set point for each of the microclimate thermal effectors is defined based upon the fuzzy set for the corresponding microclimate thermal effectors. Each microclimate thermal effector is commanded to the corresponding respective temperature set point.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to U.S. Provisional Application No.62/937,892 filed on Nov. 20, 2019.

TECHNICAL FIELD

This disclosure relates to microclimate system that provides increasedthermal comfort to the occupant using sensor fusion and fuzzy logic.

BACKGROUND

In traditional automotive HVAC or climate systems, the control systemuses temperatures from sensors mounted in different locations within thecabin or calculates temperature using a mathematical cabin thermalmodel. In recent years, seat based microclimate systems have become moredesirable because of their fast time to comfort and lower energyconsumption compared to prior systems.

An automotive seat-based microclimate system has many conductive,convective and radiative devices, like heater mats, thermo-electricdevices (TED)s, positive temperature coefficient thermistors (PTCs) andmini-compressor systems located in the seat and surrounding area.Calculating local temperature accurately for local heating/coolingdevice control is important for controlling local thermal comfort, butis difficult to achieve with current systems.

The current methods for automotive seat based microclimate systems arediscrete ON/OFF or modulated power (PWM) control based on fixedtemperature setpoints (typically 3 to 5 discrete levels). The occupantmanually selects one of these predefined temperature setpoints to adjustfor changing conditions in the vehicle and human body. Additionally,since levels are discrete, the user may be forced to change levels to“hunt” for an unobtainable setting.

Fuzzy logic has been disclosed as an option for bulk air heating andcooling in aircraft cabins. Fuzzy logic is an approach to algorithmsthat utilizes “degrees of truth” rather than the binary extremes of true(1)/false (0). Fuzzy logic includes the extreme cases, but also includesmultiple states between true and false such that the comparison betweentwo things can result in a value between true and false (e.g. the driveris comfortable is 0.45 (45%) true). Because the fuzzy logic is used toregulate the bulk air temperature, the rate of change in cabintemperature is used to create the fuzzy set rather that another metric.Regulating based upon temperature rate of change prevents undesiredoscillations in cabin temperature from overshooting the desired cabintemperature.

SUMMARY

An exemplary method of controlling a microclimate system includesidentifying a set of multiple microclimate thermal effectors configuredto provide multiple occupant zones, determining a differentialtemperature between a local temperature at one of the microclimatethermal effectors and a preset temperature for the one of themicroclimate thermal effectors, the differential temperature beingdetermined for each of the microclimate thermal effectors, andgenerating a fuzzy set for each of the microclimate thermal effectorsbased upon the respective differential temperature, defining arespective temperature set point for each of the microclimate thermaleffectors based upon the fuzzy set for the corresponding microclimatethermal effectors, and commanding each microclimate thermal effector tothe corresponding respective temperature set point.

In another example of the above described method of controlling amicroclimate system the multiple occupant zones include at least two ofa head zone, a seat back zone, a seat cushion zone, a hand/arm zone anda foot/leg zone.

In another example of any of the above described methods of controllinga microclimate system at least a portion of the set of multiplemicroclimate thermal effectors are conductive thermal devices that areconfigured to engage an occupant during use.

In another example of any of the above described methods of controllinga microclimate system the set of multiple microclimate thermal effectorsincludes microclimate thermal effectors selected from the groupcomprising climate controlled seats, head rest/neck conditioner, climatecontrolled headliner, steering wheel, heated gear shifter, heater mat,and mini-compressor system.

In another example of any of the above described methods of controllinga microclimate system the local temperature for at least one of themicroclimate thermal effectors in the set of multiple microclimatethermal effectors is determined using a negative temperature coefficientelement in the one of the microclimate thermal effectors.

In another example of any of the above described methods of controllinga microclimate system generating the fuzzy set for each of themicroclimate thermal effectors uses fuzzy rules based upon an occupantthermal sensation scale for a population of occupants and their personaloccupant thermal comfort for the multiple occupant zones.

Another example of any of the above described methods of controlling amicroclimate system further including converting the fuzzy set to afuzzy output corresponding to the temperature set point for each of themicroclimate thermal effectors.

In another example of any of the above described methods of controllinga microclimate system further including providing a feedback loop fromeach of the microclimate thermal effectors, wherein the feedback loop isconfigured to determine the differential temperature based upon thecommanded temperature set point and a measured local temperature.

In another example of any of the above described methods of controllinga microclimate system including the step of fusing temperature data todetermine the local temperature, temperature data fusing step includesproviding microclimate temperature data from each of the microclimatethermal effectors, receiving vehicle temperature data from a vehicledata bus, the vehicle temperature data including a cabin temperature andan outside air temperature, and fusing the microclimate temperature datawith the vehicle temperature data to determine a local temperature foreach of the microclimate thermal effectors.

In one exemplary embodiment a microclimate system for a vehicle occupantincludes multiple microclimate thermal effectors configured to providemultiple occupant zones, a controller in communication with themicroclimate thermal effectors, the controller configured to determine adifferential temperature between a local temperature for one of themicroclimate thermal effectors and a preset temperature for the one ofthe microclimate thermal effectors, the controller being furtherconfigured to determine the differential temperature for each of themicroclimate thermal effectors, the controller being further configuredto generate a respective fuzzy set for each of the microclimate thermaleffectors based upon a respective differential temperature of each ofthe microclimate thermal effectors, the controller being furtherconfigured to define a temperature set point based upon the fuzzy setfor each of the microclimate thermal effectors, and the controllerconfigured to command the microclimate thermal effectors to itsrespective temperature set point.

In another example of the above described microclimate system for avehicle occupant the multiple occupant zones include at least two of ahead zone, a seat back zone, a seat cushion zone, a hand/arm zone and afoot/leg zone.

In another example of any of the above described microclimate systemsfor a vehicle occupant at least a portion of the multiple microclimatethermal effectors are conductive thermal devices configured to engage anoccupant during use.

In another example of any of the above described microclimate systemsfor a vehicle occupant the microclimate thermal effectors includemicroclimate thermal effectors selected from the group comprisingclimate controlled seats, head rest/neck conditioner, climate controlledheadliner, steering wheel, heated gear shifter, heater mat, andmini-compressor system.

In another example of any of the above described microclimate systemsfor a vehicle occupant the local temperature for at least one of the oneof the microclimate thermal effectors is determined by the controllerusing a negative temperature coefficient element in the one of themicroclimate thermal effectors.

In another example of any of the above described microclimate systemsfor a vehicle occupant the fuzzy sets are generated by the controllerusing fuzzy rules based upon an occupant thermal sensation scale for apopulation of occupants and their personal occupant thermal comfort forthe multiple occupant zones.

In another example of any of the above described microclimate systemsfor a vehicle occupant the controller is configured to convert eachfuzzy set to a fuzzy output corresponding to the temperature set pointfor of the corresponding microclimate thermal effectors.

In another example of any of the above described microclimate systemsfor a vehicle occupant the controller includes a feedback loop from themicroclimate thermal effectors, wherein the feedback loop is configuredto determine the differential temperature based upon the commandedtemperature set point.

In another example of any of the above described microclimate systemsfor a vehicle occupant the controller includes an input configured toreceive vehicle temperature data from a vehicle data bus, and whereinthe vehicle temperature data includes a cabin temperature output from acabin air sensor and an outside air temperature output from an outsideair sensor.

In another example of any of the above described microclimate systemsfor a vehicle occupant the controller includes a fusion algorithmconfigured to fuse the microclimate temperature data with the vehicletemperature data to determine an expected local temperature for each ofthe microclimate thermal effectors.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure can be further understood by reference to theaccompanying drawings, comprising FIGS. 1-9 .

FIG. 1 schematically illustrates a vehicle heating ventilation andcooling system.

FIG. 2 schematically illustrates a sensor fusion processor for fusingmicroclimate sensor data and other vehicle sensor data into a singlevehicle sensor set.

FIG. 3 schematically illustrates an exemplary thermal comfort ASHRAEscale ranging from −3 to 3.

FIG. 4A illustrates an equivalent temperature for multiple regionsduring the summer.

FIG. 4B illustrates an equivalent temperature for multiple regionsduring the winter.

FIG. 5 schematically illustrates a basic architecture of an exemplarymicroclimate control system.

FIG. 6 schematically illustrates an exemplary fuzzy logic control.

FIG. 7A schematically illustrates exemplary temperature environmentfuzzy sets.

FIG. 7B schematically illustrates exemplary temperature environmentfuzzy sets.

FIG. 8 schematically illustrates an example fuzzy set based upon ΔT fora give thermal comfort effector.

FIG. 9 shows an exemplary fuzzy logic controller output plot forheating.

The embodiments, examples and alternatives of the claims, or thefollowing description and drawings, including any of their variousaspects or respective individual features, may be taken independently orin any combination. Features described in connection with one embodimentare applicable to all embodiments, unless such features areincompatible.

DETAILED DESCRIPTION

This disclosure relates to a microclimate system that provides increasedthermal comfort to the occupant by controlling microclimate thermaleffectors using sensor fusion and fuzzy logic.

Referring to FIG. 1 , a vehicle 100 has a heating, ventilation and airconditioning (HVAC) system 110 that is used to condition the air 112 andcontrol the bulk temperature of the air within the vehicle cabin 102. Atypical HVAC system 110 has ducting that supplies conditioned air 112 tothe cabin 102 using a blower 114 moving air over a heat exchanger 116. Asensor 118 monitors the temperature of the conditioned cabin air 112,and a controller 120 regulates operation of the HVAC system 110 to atemperature set point that is typically manually adjusted by an occupant104. The central HVAC 110 system is insufficient to achieve thermalcomfort for each specific occupant 104 and location in many scenarios,such as those where multiple different occupants 104 are in the samecabin 102, so microclimate devices or thermal effectors are used tocreate a unique microclimate for each occupant 104 in the cabin 102,thereby providing improved overall thermal comfort for each occupant104.

As a further challenge to providing an effective climate control system,each occupant 104 typically has unique personal comfort preferences.That is, a particular occupant 104 detects a level of thermal energydifferently than another occupant 104. As a result, the exact samethermal environment within a vehicle 100 may be perceived as comfortableby one occupant 104, but as uncomfortable by another occupant 104. Tothis end, the vehicle 100 includes an integrated approach to humanthermal management by controlling both the central HVAC system 110, orany other thermal control system in the vehicle 110, as well as variousmicroclimate thermal effectors using fuzzy logic to coordinate andoptimize comfort for each occupant 104 of the vehicle 100.

With continuing reference to FIG. 1 , an example microclimate system mayhave multiple discrete occupant microclimate zones. According to ISO145045-2:2006 (E), a human body can be divided into different bodysegments, such as hand, head or chest, and each segment has a differentthermal comfort temperature range. The five example microclimate zonesin FIG. 1 are: head 132, back 134, cushion 136 (thigh and buttocks),foot/leg 138, and arm/hand 130. Fewer, more and/or different zones maybe used if desired, depending on the specific microclimate system andthe needs of a given vehicle. In the disclosed microclimate system anestimated local equivalent temperature T_(local) is calculated on a perdevice/body region basis, i.e., by individual zones 130, 132, 134, 135,136, 138.

Microclimate thermal effectors are localized components that can adjustor maintain a desired microclimate in a corresponding zone 130, 132,134, 136, 138. The microclimate thermal effectors can include, forexample, climate controlled seats (e.g., U.S. Pat. Nos. 5,524,439 and6,857,697), a head rest/neck conditioner (e.g., U.S. Provisional App.No. 62/039,125), a climate controlled headliner (e.g., U.S. ProvisionalApp. No. 61/900,334), a steering wheel (e.g., U.S. Pat. No. 6,727,467and U.S. Pub. No. 2014/0090513), a heated gear shifter (e.g., U.S. Pub.No. 2013/0061603, etc.), heater mats, a mini-compressor system, and/orany other systems configured to achieve a personalized microclimate. Theenumerated microclimate thermal effectors are exemplary in nature andare non-limiting. The microclimate system provides a correspondingoccupant 104 personal comfort in an automated manner with little or noinput from the corresponding occupant 104. All or some of themicroclimate thermal effectors can be arranged to optimally control thethermal environment around an occupant of a seat located anywhere insidea passenger vehicle. In addition, the microclimate thermal effectors canbe used to regulate thermal comfort separately for individual segmentsof the occupant's body.

Occupant variables such as activity level and clothing are alsoconsidered by a local equivalent homogeneous temperature (EHT) model byconsidering the season, outside air temperature (determined via anoutside air sensor 118) and/or the region. User information such asgender, height, weight and age may also be provided to a sensor fusionprocessor in the controller 120. By combining the data from a vehicledata bus 140 (e.g., CAN, LIN, PWM HVAC signal, or any other data bus)and feedback from local conductive, radiative or convectiveheating/cooling microclimate thermal effectors within a headrest 150, aseat back 152, a seat cushion 154, a floormat 156, a steering wheel 158,each microclimate system accurately estimates the local equivalenthomogenous temperature, or estimated local equivalent temperature,T_(local), for the corresponding zone 130, 132, 134, 136, 138 which isthen used for local thermal comfort prediction and heating/coolingcontrol. Thus, a discrete local temperature can be obtained with themicroclimate thermal effectors at each of the five regions of theoccupant's body.

The sensor fusion method provides an efficient and accurate way toestimate local environment temperatures at each of the microclimatezones 130, 132, 134, 136, 138. Referring to FIG. 2 , a sensor fusionprocessor 200 acquires vehicle cabin temperature/velocity 202, outsideair temperature 204, sun load 206, vehicle speed and/or other data froma vehicle data bus 210 or from any available in vehicle sensors 160 (seeFIG. 1 ) and includes a sensor fusion controller 210.

The sensor fusion controller 210 acquires temperature feedback from eachthermal effector (i.e. each local heating/cooling device). Exemplaryautomotive seat-based occupant thermal comfort control systems canutilize many conductive, convective or radiative heating and coolingdevices to achieve optimal occupant comfort.

In the example microclimate system, multiple microclimate thermaleffectors are configured to thermally condition multiple occupant zones130, 132, 134, 136, 138. Each of the microclimate thermal effectorsgenerates microclimate temperature data, which is provided by atemperature sensor (e.g., a negative temperature coefficient (NTC)element) that is incorporated into each of the microclimate thermaleffectors 220. Non-limiting examples of microclimate thermal effectors220 include climate controlled seats, head rest/neck conditioners,climate controlled headliners, steering wheels, heated gear shifters,heater mats, other heated surfaces and mini-compressor systems. Otherexample microclimate thermal effectors include radiative console and/ordoor surfaces, radiant heater panels, and liquid loop based coolingdevices (devices which convert conditioned glycol to localized cooling).

One or more controllers 230 within the sensor fusion controller 200 arein communication with each of the microclimate thermal effectors 220.The controller 230 includes one or more inputs 212 configured to receivevehicle temperature data from a vehicle data bus 210. The controller 230fuses the microclimate temperature data 222 received from themicroclimate thermal effectors 220 with the vehicle temperature datareceived from the vehicle data bus 210 using an algorithm (e.g.Equation 1) to determine an estimated local equivalent temperatureT_(local) for each of the microclimate thermal regions/zones. Thecontroller provides a temperature command 224 to each of themicroclimate thermal effectors 220 based upon its estimated localequivalent temperature T_(local) to achieve occupant thermal comfort ateach individual zone 130, 132, 134, 136, 138.

One example sensor fusion equation (Equation 1) calculates estimatedlocal equivalent temperature T_(local) for each microclimate thermalregion/zone, as follows.

T _(local) =W ₁×(T _(cabin) +b _(tv))+W ₂ ×T _(outside) +W ₃ ×SL _(nor)+W ₄ ×V+W ₅ ×T _(lf)

Where: W₁ i=1, 2, 3, 4, 5; calibratable weighting factor

-   -   T_(cabin) cabin temperature    -   b_(tv) temperature vertical stratification factor or offset    -   T_(outside) outside temperature    -   SL_(nor) normalized sunload    -   V vehicle peed    -   T_(lf) local effector temperature feedback

The vehicle temperature data includes cabin temperature T_(cabin),outside air temperature T_(outside), vehicle solar load SL_(nor) andvehicle speed V. The weighting factors W_(i) may be different based uponthe particular microclimate thermal effector 220. A skilled artisan canselect the particular weighting factor to be used for each controlportion (i) based on the particular microclimate thermal effectors 220and the expected/experienced conditions of the thermal effector(s) 220affecting the control portion (i).

Most vehicles have a single interior air temperature sensor, but if onewere to measure local temperatures inside the vehicle at any given timethe temperatures would be very different, especially if you have a sunnyday (i.e. the vehicle has a high solar load). The algorithm allowsadjustments based on how well the interior cabin sensor actuallycorrelates to local temperatures and is unique for each car. Thetemperature vertical stratification or offset b_(tv) adjusts the cabinair temperature for the level of stratification in a particular zonee.g. “breath level” would be used in the zone around the head of theoccupant 104. Similarly, if the cabin air temperature sensor is locatedat approximately the same level as the steering wheel, then there may beno offset for back zone 134 and the hand/arm zone 130. However, theremay be a negative offset for the foot/leg zone 138 or the seat zone 136,and a positive offset for the head zone 132. The weighting factor W₁provides further adjustments for each microclimate thermal region/zone130, 132, 134, 136, 138. For example, the cabin temperature in the headzone 132 may have a greater weighting factor W₁ than the hand/arm zone130.

Weighting factor W₂ adjusts the outside temperature and its effects oneach microclimate thermal effector. For example, the outside temperaturein the hand/arm zone 130 may have a bigger weighting factor than in theseat zone 136. In a cold ambient when the vehicle is travelling quickly,additional “work” is needed from the door heaters to overcome the lossof heat through the door and side glass.

The vehicle solar load SL_(nor) is normalized, and a weighting factor W₃is applied to the vehicle solar load SL_(nor) to account for aparticular body segment which has direct sun exposure. For example, witha panoramic sun roof more solar radiant heating would enter the cabinand impact comfort. Conversely, the impact of sun could be reduced ifthe vehicle has special solar glazing, which reflects sun load.

Weighting factor W₄ adjusts for the effects of vehicle speed on theparticular zone. The foot/leg zone 138 is particularly susceptible toeffects of vehicle speed on local temperature. For example, the foot/legzone 138 becomes particularly cold at high speeds in cold temperatures,so a larger weighting factor may be used for the foot/leg zone 138. Thevehicle speed may have negligible effects on the back zone 134, forexample, so the weighting factor may be used to zero-out the vehiclespeed for the seat back thermal effector(s).

The microclimate temperature data 222 includes thermal effector feedbackT_(lf) that may also be adjusting using a weighting factor W₅. Forexample, the hand/arm zone 130 thermal effector(s) 220 may be givenincreased weight when a steering wheel heater is used, as that can havea large impact on occupant comfort in the hand/arm zone 130.

The effectiveness of the disclosed system is, in some examples, furtherenhanced by using fuzzy logic to predict the human body's thermalsensation and thereby the comfort of the human body in real time. Byemploying fuzzy logic control, each device in the system isautomatically tuned to the correct temperature and flow rate set pointbased on the local environmental condition to meet the occupant's localbody segment's thermal comfort expectations. Since each occupants'thermal expectations are unique, fuzzy logic is used to define atemperature set point for each thermal effector in such a manner thattakes into account thermal comfort variations in an occupant population.

In one example, an occupant thermal condition is expressed as the degreeto which an occupant senses a hot or cold temperature, or changes andvariations in temperature. These hot and cold sensations are representedusing an ASHRAE (American Society of Heating, Refrigerating andAir-Conditioning Engineers) thermal sensation scale 310 from 3 (hot) to−3 (cold), as shown in FIG. 3 , according to a predicted mean vote (PMV)methodology 320. In the disclosed system, the PMV calculation assigns a“hotness”/“coldness” value for each microclimate zone.

As an alternative to the hot and cold sensation scale shown in FIG. 3 ,an occupant thermal condition can be expressed using the BerkeleySensation and Comfort Scale (“Berkeley scale”), described in, forexample, Arens E. A., Zhang H. & Huizenga C. (2006) Partial- andwhole-body thermal sensation and comfort, Part I: Uniform environmentalconditions. Journal of Thermal Biology, 31, 53-59. It should beunderstood that other approaches can be used to quantify an occupant'sthermal condition.

The season may significantly affect the perceived occupant thermalcomfort such that the PMV 320 outcome is different. So, the predictedoccupant thermal comfort 400 may be adjusted based upon the season, asshown in FIGS. 4A and 4B, with FIG. 4A illustrated an equivalenttemperature for multiple regions 410A during summer and FIG. 4Billustrating an equivalent temperature for the multiple regions 410Bduring the winter. Although only a five-value thermal scale is shown inFIGS. 4A and 4B (“too cold,” “cold but comfortable,” “neutral,” “hot butcomfortable,” and “too hot”), it is appreciated that the thermal comfortcan be further refined to correlate to the seven-value ASHRAE thermalsensation scale 310 (3 to −3) shown in FIG. 3 .

FIG. 5 schematically illustrates the basic architecture of an exemplarymicroclimate control system 500 that uses both sensor fusion 510 andfuzzy logic control 520 (illustrated in more detail in FIG. 6 ) toregulate each of the microclimate thermal effectors 530. The sensorfusion control scheme 500 compensates for important factors that affectoccupant comfort including both environmental conditions 512 external tothe vehicle and environmental conditions 514 within specific stratifiedlayers of the cabin volume. The local effector temperature feedbackT_(LF) 532 (Feedback T) is provided in one example by a negative thermalcoefficient (NTC) temperature sensor that is integrated into eachthermal effector within each zone. The values from the local fuzzy logiccontroller 520 and NTC feedback 532 are provided to the PWM controller540 to regulate the thermal effector 530. Other control functions may beused such as overheat protection, maximum temperature limits from thePWM controller, maximum holding times for a given temperature setpointand the like, according to conventional control methodologies.

Referring to FIGS. 5-6 , the local fuzzy logic controller 520establishes temperature based fuzzy sets which are related to each localbody segments' temperature range for comfort. Fuzzy rules are createdaccording to each physical heating/cooling device's characteristics andlocation, and the fuzzy controller applies “fuzzy logic” in theautomotive seat based occupant thermal comfort system (including othermicroclimate thermal effectors) to control each individualheating/cooling device's temperature dynamically.

As explained above in connection with the sensor fusion algorithm, theoccupant thermal comfort system is divided into multiple comfort controlzones (e.g., five) based on up to nineteen body segments andcorresponding effectors in each seat location. The number of controlzones can be more than five and up to nineteen (defined in ASHRAE model)according to unique conditions around the body. Approximately five zonesare desirable in some examples from a perspective of user input to thesystem for customization and control due to the reduced complexity whilethe relationship between five comfort control zones and nineteen, forexample, can be established mathematically, in order to translate fromcomfort related parameters to control related parameters.

There may be several heating and/or cooling devices impinging on theclimate in each of the comfort control zones. Each of these devices mayhave its own control module. FIG. 5 shows the major functionalsubsystems within a typical heating and/or cooling control module 500.

After collecting the vehicle data and feedback from all comfort controldevices, the system generates localized temperature information for eachcontrol module based on the device location. The control modulecalculates ΔT 550 based on the local temperature and desired comforttemperature for the zone. In particular, ΔT 550 corresponds to the localtemperature based upon the vehicle temperature data minus the desired,preset local comfort temperature for the given thermal effector. Thefuzzy logic controller 520 takes ΔT 550 as the input and converts ΔT 550into a fuzzy membership function through fuzzification. According toASHRAE thermal sensation scale, ISO 14505-2:2006 and each individualheating/cooling device's physical characteristics, location andcorresponding body segments the exemplary system 500 defines fourenvironment temperature fuzzy sets 560, 562, 564, 566 (member functions)for each zone, as shown in FIG. 7A, and 4 fuzzy sets 570, 572, 574, 576for heating/cooling set temperatures, as shown in FIG. 7B. The fuzzylogic controller 520 applies fuzzy rules and decides the output value,i.e., the inference mechanism. Through defuzzification, the controlmodule 540 converts the fuzzy output to real life data value which isused as a temperature set point for the device. FIG. 6 is a typicalcontrol flowchart for designing a fuzzy logic controlled heating/coolingdevice.

The temperature set point 552 is provided to the controller 540, whichuses any suitable control scheme to provide a pulse width modulation(PWM) signal 542 to the given thermal effector 530 controlling thethermal effector 530 to the setpoint. The NTC within the thermaleffector 530 provides feedback to the sensor fusion algorithm 510, aswell as a summing junction 534 between the temperature set point toprovide a corrected signal to the control scheme.

The fuzzy sets account for the uncertainty relating to the applicationof the ASHRAE thermal sensation scale to any given occupant. The “1”value indicates 100% certainty that the entire population would agreewith the indicated thermal sensation, and the “0” value indicates thatthe entire population would disagree with the indicated thermalsensation. An example of the fuzzy sets based upon ΔT 550 for a givethermal comfort effector 530 is shown in FIG. 7A and the left side ofFIG. 8 . The sloped lines reflect the variation within the population asto whether the indicated thermal sensation applies to the population ofoccupants. Where sloped lines overlap at a given ΔT 550, the populationis divided as to its perceived thermal comfort. For example, at −10 ΔT550, 50% of the population would feel “slightly cool”, and 50% of thepopulation would feel “neutral.” The fuzzy sets are determined using theΔT 550 to produce the temperature set point 552 for the given thermaleffector, as shown in FIG. 7B and the right side of FIG. 8 . Thespecific values illustrated in FIGS. 7A, 7B and 8 are exemplary only andthe values will vary depending on the specifics of the system 500 andthe thermal effector 530.

FIG. 9 shows an exemplary fuzzy logic controller output plot 600 forheating. The output plot 600 discloses multiple exemplary regions 610,620, 630, 640, 650 with 610 representing the “0” value where no userswould be comfortable and 650 representing the “1” value where every useris comfortable. Intervening regions 620, 630, 640 represent intermediateregions where some users are expected to be comfortable and other usersare expected to be uncomfortable.

The fuzzy logic control temperature can be based on SISO (single inputsingle output) 1D control or MIMO (multiple inputs multiple outputs)multi-dimensional control. Additional inputs and outputs can beincluded, such as fan airflow rate, humidity etc. and the controls canbe implemented according to any SISO or MIMO control scheme.

It should also be understood that although a particular componentarrangement is disclosed in the illustrated embodiment, otherarrangements will benefit herefrom. Although particular step sequencesare shown, described, and claimed, it should be understood that stepsmay be performed in any order, separated or combined unless otherwiseindicated and will still benefit from the present invention.

Although the different examples have specific components shown in theillustrations, embodiments of this invention are not limited to thoseparticular combinations. It is possible to use some of the components orfeatures from one of the examples in combination with features orcomponents from another one of the examples.

Although an example embodiment has been disclosed, a worker of ordinaryskill in this art would recognize that certain modifications would comewithin the scope of the claims. For that reason, the following claimsshould be studied to determine their true scope and content.

What is claimed is:
 1. A method of controlling a microclimate systemcomprising: identifying a set of multiple microclimate thermal effectorsconfigured to provide multiple occupant zones; determining adifferential temperature between a local temperature at one of themicroclimate thermal effectors and a preset temperature for the one ofthe microclimate thermal effectors, the differential temperature beingdetermined for each of the microclimate thermal effectors; generating afuzzy set for each of the microclimate thermal effectors based upon therespective differential temperature; defining a respective temperatureset point for each of the microclimate thermal effectors based upon thefuzzy set for the corresponding microclimate thermal effectors; andcommanding each microclimate thermal effector to the correspondingrespective temperature set point.
 2. The method of claim 1, wherein themultiple occupant zones include at least two of a head zone, a seat backzone, a seat cushion zone, a hand/arm zone and a foot/leg zone.
 3. Themethod of claim 2, wherein at least a portion of the set of multiplemicroclimate thermal effectors are conductive thermal devices that areconfigured to engage an occupant during use.
 4. The method of claim 3,wherein the set of multiple microclimate thermal effectors includesmicroclimate thermal effectors selected from the group comprisingclimate controlled seats, head rest/neck conditioner, climate controlledheadliner, steering wheel, heated gear shifter, heater mat, andmini-compressor system.
 5. The method of claim 3, wherein the localtemperature for at least one of the microclimate thermal effectors inthe set of multiple microclimate thermal effectors is determined using anegative temperature coefficient element in the one of the microclimatethermal effectors.
 6. The method of claim 2, wherein generating thefuzzy set for each of the microclimate thermal effectors uses fuzzyrules based upon an occupant thermal sensation scale for a population ofoccupants and their personal occupant thermal comfort for the multipleoccupant zones.
 7. The method of claim 6, further comprising convertingthe fuzzy set to a fuzzy output corresponding to the temperature setpoint for each of the microclimate thermal effectors.
 8. The method ofclaim 1, further comprising providing a feedback loop from each of themicroclimate thermal effectors, wherein the feedback loop is configuredto determine the differential temperature based upon the commandedtemperature set point and a measured local temperature.
 9. The method ofclaim 8, comprising the step of fusing temperature data to determine thelocal temperature, temperature data fusing step includes: providingmicroclimate temperature data from each of the microclimate thermaleffectors; receiving vehicle temperature data from a vehicle data bus,the vehicle temperature data including a cabin temperature and anoutside air temperature; and fusing the microclimate temperature datawith the vehicle temperature data to determine a local temperature foreach of the microclimate thermal effectors.
 10. A microclimate systemfor a vehicle occupant comprising: multiple microclimate thermaleffectors configured to provide multiple occupant zones; a controller incommunication with the microclimate thermal effectors, the controllerconfigured to determine a differential temperature between a localtemperature for one of the microclimate thermal effectors and a presettemperature for the one of the microclimate thermal effectors, thecontroller being further configured to determine the differentialtemperature for each of the microclimate thermal effectors, thecontroller being further configured to generate a respective fuzzy setfor each of the microclimate thermal effectors based upon a respectivedifferential temperature of each of the microclimate thermal effectors,the controller being further configured to define a temperature setpoint based upon the fuzzy set for each of the microclimate thermaleffectors, and the controller configured to command the microclimatethermal effectors to its respective temperature set point.
 11. Themicroclimate system of claim 10, wherein the multiple occupant zonesinclude at least two of a head zone, a seat back zone, a seat cushionzone, a hand/arm zone and a foot/leg zone.
 12. The microclimate systemof claim 11, wherein at least a portion of the multiple microclimatethermal effectors are conductive thermal devices configured to engage anoccupant during use.
 13. The microclimate system of claim 12, whereinthe microclimate thermal effectors include microclimate thermaleffectors selected from the group comprising climate controlled seats,head rest/neck conditioner, climate controlled headliner, steeringwheel, heated gear shifter, heater mat, and mini-compressor system. 14.The microclimate system of claim 12, wherein the local temperature forat least one of the one of the microclimate thermal effectors isdetermined by the controller using a negative temperature coefficientelement in the one of the microclimate thermal effectors.
 15. Themicroclimate system of claim 11, wherein the fuzzy sets are generated bythe controller using fuzzy rules based upon an occupant thermalsensation scale for a population of occupants and their personaloccupant thermal comfort for the multiple occupant zones.
 16. Themicroclimate system of claim 15, wherein the controller is configured toconvert each fuzzy set to a fuzzy output corresponding to thetemperature set point for of the corresponding microclimate thermaleffectors.
 17. The microclimate system of claim 10, wherein thecontroller includes a feedback loop from the microclimate thermaleffectors, wherein the feedback loop is configured to determine thedifferential temperature based upon the commanded temperature set point.18. The microclimate system of claim 17, wherein the controller includesan input configured to receive vehicle temperature data from a vehicledata bus, and wherein the vehicle temperature data includes a cabintemperature output from a cabin air sensor and an outside airtemperature output from an outside air sensor.
 19. The microclimatesystem of claim 18, wherein the controller includes a fusion algorithmconfigured to fuse the microclimate temperature data with the vehicletemperature data to determine an expected local temperature for each ofthe microclimate thermal effectors.